Clutch operating mechanism



Aprilzl, 1936.

F. LINDER CLUTCH OPERAT ING MECHANI SM Filed Feb.. 27, 1952 2Sheets-Sheet 1 April 2l, 1935- F. LINDER 2,038,182

CLUTCH OPERATING MECHANISM Filed Feb. 27, 1932 2 Sheets-Sheet 2 mnu:Linder Patented Apr. 2l, 1936 l PATENT OFFICE aosaisz CLUTCH OPERATINGMECHANTSM Francis Linder, East Orange, N. J., assignor, by

mesne assignments, to Eclipse Aviation Corporation, East Grange, N. J.,a corporation of Ne Jersey Application February 27, 1932, Serial No.l595,642

4 Claims.

This invention relates to engine starting apparatus and moreparticularly to apparatus for starting airplane engines, although notnecessarily confined to such use.

An object of the invention is to provide novel means for controlling thetorque transmitting capacity of a starter of the foregoing character;but in its broader aspects the invention provides novel capacitycontrolling means for driving mechanisms in general.

A further object of the invention is to provide in a driving mechanismof the type in which the driving torque is transmitted to a member to bedriven through a friction clutch, novel means for maintaining the torquecapacity of said clutch constant during the entire period of torquetransmission, regardless of any change occurring in the coefficient offriction of the driving surfaces of the clutch.

Another object of the invention is to provide a clutch mechanism of theforegoing character wherein any tendency for the torque capacity of theclutch to vary, due to heat responsive expansion of the elements thereofor for any other reason will automatically produce a counter-actingtendency operating to maintain the torque at its normal predeterminedvalue.

Still another object of the invention is to provide in a device of theforegoing character, novel clutch setting means whereby a relatively lowpressure, insufficient to interfere with or retard the meshing actionexists during the pre-meshing period.

Another object of the invention is to provide clutch controlling meansof the nature just described and further characterized by the provisionof means for automatically increasing the torque transmitting capacityof the friction clutch in response to the load applied thereto by virtueof the completion of the meshing action. In this connection a feature ofthe invention is the provision of novel pressure applying meansoperative automatically in response to the continued rotation of theclutch driving elements immediately following the establishment of acondition of complete mesh.

These and other objects and advantages to be derived from the use of theinvention herein disclosed involve the inter-relation and relativefunction of.' the parts and will become apparent upon inspection of thefollowing specification, reference being had to thel accompanyingdrawings, wherein the preferred embodiment of the invention isdisclosed. It is to be understood however, that the drawings are for thepurpose of (Cl. 12S-179) illustration only and are not designed as adefinition of the limits of the invention, reference being had forsuchpurpose to the appended claims.

In the drawings,

Fig. 1 is a longitudinal sectional view oi a device embodying theinvention;

Fig. 2 is a View in elevation of certain of the parts involved in thenovel clutch controlling action;

Fig. 3 is a schematic representation of the relative position of certainof the parts shown in Fig'. 2, as such parts appear prior to applicationof load thereto;

Fig. 4 is a similar schematic representation of the same parts as theyappear after the application of load thereto;

Fig. 5 is a transverse sectional view along the line 5 5 of Fig. 2; andj Fig. 6 is a schematic representation of a modiflcation of the partsshown in Figs. 3 and 4;

Referring to thedrawings, the starting mechanism therein shown comprisesa flywheel 5 adapted to rotate an engine-engaging member or clutch jaw 6which is movable into driving engagement with a jaw member 'I providedon an engine crankshaft (not shown) or an extension thereof. Thestarting apparatus includes a housing constituted by an inner section 8,an intermediate section 9 and a flywheel cover section I0, the

sections being removably secured together in any suitable manner and theinner section being provided with a flange II to facilitate mounting ofthe starter on the crankcase,` a portion of which is shown at I2.

The intermediate housing section 9 is provided adjacent the outer endthereof with an irregularly shaped wall or diaphragm I3 having a boss I4formed centrally thereof to receive the flywheel 5. The flywheel isadapted to be rotated at high speed on bearings I5 in order thatsufflcient energy may be stored therein for cranking the engine, and agear train is preferably provided for transmitting the energy stored inthe flywheel to the engine-engaging member 6, the gear train being soconstituted that member 6 will be rotated at a much lower speed thanthat of the flywheel. For this purpose a. shaft I6 extends through thehub of the flywheel and` is drivably connected thereto by means of a keyI'I. The inner-end of shaft I6 is provided with a flange I8 whichengages bearings I5 and coacts with a nut I9 threaded onto the'l outerend of' the shaft and abutting the flywheel to prevent longitudinalmovement of the shaft relative to said ywheel. Shaft I6 is providedclosely adjacent flange I8 with a. pinion 20 that meshes with a spurgear 2| formed on the large end of a bell shaped member 22 that isrotatably mounted as by means of a stub shaft 23 in an elongated boss 24formed in the wall I3. Ball bearings 25 are preferably provided forrotatably mounting shaft 23.

Formed integrally with the bell shaped member 22 and shaft 23, orrigidly connected thereto in any suitable manner, is a pinion 26 whichmeshes with an internal spur gear 21 that is coaxially disposed relativeto the flywheel 6. Gear 21 is formed integrally with a pinion 28 that isrotatably mounted by means of a bearing 29 on a stub shaft 30 which issplined to and projects centrally from the closed end of a barrel 3|rotatably mounted in inner housing section 8 by means of ball bearings32.

Pinion 28 constitutes a sun gear for a plurality of planetary gears 33,one of which is shown in section in Fig. l. Preferably three planetarygears are employed, the same being spaced at intervals of about theclosed end of barrel 3|, and said gears mesh with an internal gear 33nwhich is rigidly secured in any suitable manner to the inner surface ofhousing section 8. Each planetary gear is rotatably mounted by means ofa ball bearing 34 on a sleeve 35 having the inner end thereofcountersunk in the outer face of the closed end of the barrel. A screw36 extends through the sleeve and is threaded into the end of saidbarrel. A ring 36B is carried by the outer ends of the screws 36 andconstitutes a retaining member for the ball bearings 34 and sleeves 35.

Means are preferably interposed between the gear train described aboveand the engine-engaging member 6 for yieldingly transmitting the energyin the flywheel to the engine crankshaft without damage such as mightresult if the driving connections were entirely constituted by rigidlyconnected elements. For this purpose a multiple disc clutch ispreferably employed, said clutch being mounted in barrel 3|.

As shown, the clutch comprises a plurality of annular discs 31, certainof the discs being splined at their outer peripheries to the innersurface of barrel 3|, and the remaining discs being splined at theirinner peripheries to the outer surface of a sleeve 38 which is providedat one end with a flange 10. The clutch discs are positioned betweeniiange 10 and a pressure ring 40 contacting with the closed end ofbarrel 3|; adjustable yielding means being provided for holding sleeve38 in operative position with respect to the discs and barrel and forvarying the frictional engagement of said discs.

In the illustrated embodiment the yielding means comprises a pluralityof coil springs 4| which extend longitudinally within the barrel; theouter ends of said springs having operative association with the flange10 through the novel torque responsive means to be described. An annularplate 4| l provided with a plurality of laterally projecting studs 42,is mounted in the barrel with the studs extending into the coils of thesprings whereby the latter are maintained in proper spaced relation. Anadjusting nut 43 is threaded into the open end of the barrel and hasabutting engagement with the inner face of plate 4in. By adjusting theposition of nut 43 longitudinally of barrel 3| the compression ofsprings 4| may be changed to vary the pressure with which the clutchdiscs or plates 31 are engaged.

Exteriorly threaded onto the inner end of barrel 3| is a ring 44 forretaining the adjacent ball bearing 32. Ring 44 may be locked inposition by means of a wire 45, and-said ring is adapted (in conjunctionwith a shoulder 46, provided on the outer end of the barrel and havingengagement with the inner race of outer ball bearing 32) to preventendwise movement of the barrel relative to the inner housing section 8.

Positioned within sleeve 38 is a threaded shaft 41 adapted for rotaryand longitudinal movement relative to said sleeve. The outer end of saidshaft is provided with suitable means such as a. nut 48 adapted toengage a shoulder formed interiorly of member 41 (to be furtherdescribed) to limit longitudinal movement of the shaft to the left asviewed in Fig. 1. The inner end of shaft 41 is longitudinally splinedandvextends into the correspondingly splined hub portion 6a of clutchmember 6 whereby these parts have positive driving engagement, but areadapted for relative longitudinal movement. A coil spring 49 whichpreferably has its outer end extending into a recess invshaft 41 isinterposed between said shaft and the jaw member 6, and yieldinglyresists movement of the jaw member toward the shaft. Such movement maybe effected at the proper time due to the engagement of the shoulder 60of rod 6| with the end of shaft 41, the rod 6| being operable through asuitable lever 62 extending out through the casing section 9. Means(manually or power operable) are provided for rotating the flywheel 5 tostore energy therein. As shown, said means includes a cranking shaft 5|]which is rotatably mounted in housing section 9 with the -outer endthereof projecting exteriorly of said housing to receive a handcrank orpower member (not shown). Shaft 50 is rotatably supported in the sidewall of section 9 by means of a ball bearing 52 and the inner end ofsaid shaft, which extends substantially at right angles to the axis ofrotation of flywheel 5, is rotatably supported in a boss 53 provided inwall I3, by means of a roller bearing 54. The inner end of shaft 50 hasrigidly connected thereto a bevel gear 55 which mesheswith a bevel gear56 shown as integral with stub shaft 30. Having -thus described oneknown combination of starter elements, to which the preferred embodimentof the present invention is readily adaptable, there will now bedescribed the elements constituting said preferred embodiment as hereinillustrated.

Referring principally to Figs. 2 and 5, the invention is shown embodiedin a plurality of Wedging members in the form of rollers 66 disposedWithin a retaining ring 65, each of said rollers having a frusto-conicaloutline with the converging elements of the lateral surfaces thereofcoinciding with the radii of a spher'e, the center of which is locatedat the point of intersection between the axis of rotation of the unitandthe plane at right angles thereto and vertically bisecting each ofsaid rollers. As will be evident hereinafter, however, the Wedgingaction does not depend upon the conical characteristic of the members 66and said members may in fact be of other shapes, such-as spherical,provided they are disposed in the manner illustrated, to wit, incooperating recesses 61 and 68 formed at equal radial intervals aboutthe opposing faces of the members 69 and 19 respectively, the latterbeing shown as a flange extendedradially from the sleeve 38 at a pointin parallel relation with a pressure plate 12 located at one end of theclutch assembly 31. 'Ihe member 69 is likewise shown as a flangedportion of a sleeve or nut 14v having a relatively smooth outer surfaceof substantially the same diameter as the inner diameter ot the sleeve38, and having an inner surface coarsely threaded to correspond to thethread on the outer surface of the shaft 41. Thereby rotary movementofthe nut 14 may produce limited longitudinal motion of the shaft 41 dueto the provision of such cooperating threads. As shown, the flange 66 ofthe sleeve 14 is located intermediate the ends of saidsleeve and isadapted to be engaged on the surface remote from the rollers 66 byanother series of rollers 19 held in relation thereto by the provisionof an annular plate 80 having its outer periphery splined to cooperatewith the splines on the inner surface of the barrel 3| and adapted to becontacted by the ends of the coil springs 4|, above described, the saidrollers 19 thus acting as thrust bearings when relative rotation occursbetween the said barrel 3| and the nut 14, in the manner which willpresently appear.

In operation. the flywheel 5 is accelerated to the desired speed byeither hand or power means applied to the shaft 50, and through theintermediary gears 55, 56, barrel 3| and gears 33, 26, 21, 26, 2| and20, the concurrent rotation of the. barrel 3| being communicated throughthe clutch plates 31 (these plates being held in frictional engagementby only a relatively light pressure during this stage of the operation)to the sleeve 38. Rotation of the sleeve 38 is in turn communicated tothe nut 14 through the Wedging rollers 66,' which during this period ofcomparatively no load-the jaw clutch 6 being out of contact with theengine member '1 -occupy the relative position, axially, indicated inFigs. 2 and 3. Since there is no axial pressure being applied this timeto the shaft 41, and since there is no constraint on this member or onthe jaw clutch 6, both these elements rotate idly as a unit with the nut14. As soon, however, as the ywheel 5 has been accelerated to thedesiredspeed and the rod 6| urged to the left to mesh the jaw 6 with the enginemember 1 through the intermediate members 41and 49, the resultant loadand resistance to rotation placed upon the elements 6 and 41 causes aretardation of the nut relatively to the sleeve 38, with the result thatthe rollers 66 are urged along the inclined surfaces of the recesses 61and 68, thereby causing the flanges 69 and to be spread apart and aresultant compression of the springs 4|. As this compressing actioncontinues, the torque transmitting capacity of the clutch plates 31increases correspondingly until a condition is reached wherein thetorque applied to the sleeve 38, and thence to the rollers 66,substantially balances the spring pressure applied to the clutch. Thiscondition is reached when the rollers 66, in their climb along theslopes of their respective recesses, have moved through an angle whosetangent is the ratio which the pressure of springs 4| (expressed inpounds) 'bears to the driving torque, expressed in pounds,

plus the co-eilicient of friction of the rollers. When this occurs,relative rotation ceases, and there follows a 4comparatively positivedrive from the barrel 3| to the jaw clutch 6, now in cranking relationto the engine member 1.

In the event of a decrease in the coemcient of friction Vof the surfacesof the clutch discs due to the heat generated therein, or due to anyother cause, or in the event of any tendency of the discs to expand dueto such heat absorption, the torque transmitting capacity neverthelessremains at the preset amount. since any such increase producesautomatically a compensating shifting of the rollers 66, sol as toestablish a new angle which varies from the old by an amountcorresponding to the angle whose tangent is equivalent to the differencebetween the old and the new co-eillclents of friction. In this newposition the new axial ycomponent of the driving i torque will differfrom the old by exactly the amount of change in the spring pressure,thereby maintaining equilibrium. 'Ihe result of such equilibrium is tomaintain the effective component of the driving torque constantregardless of how lmuch the axial component thereof may change in orderto balance the variations in the degree of spring compression.

As soon as the engine is tarted under its own power, the inclinedsurfaces of the engine clutch "member 1 act to return the starter clutchmember 6 to the position indicated in Fig. 1, the spring plicable to anyknown type of starter wherein the driving torque is transmitted to amember ofthe engine to be started through a clutch connection,

the invention being so applicable without entailing any expensiveaddition to or alterations in such starters as now used. While theembodiment of the invention herein disclosed possesses considerablepractical merit, it is understood that the invention is not limited tothe form shown in the drawings, but is capable of a variety ofmechanical embodiments.v For example, in order to render the clutchcontrol effective for either diretion of rotation, the members 69 and 10may be varied in form as indicated at 90 and 9|, respectively, in Fig.6. These changes consist in grooving the recesses 61 on either side ofeach roller 66, as shown at 90, also in providing corresponding tongues93 on 'the member 10, these tongues extending from depressions 9| in theotherwise straight bevelled edge 92 of the said member 10. As shown, thetongues are spaced so as to be symmetrical with the associated grooves90. With this construction it is apparent that the rollers 66 will be atall times constrained for movement lin unison with the member 10, whilerelative load responsive movement between the rollers and the members 69will be possible in either a clockwise or counter-clockwise direction,depending upon the direction of rotation of the starter.

Various other changes, which will now suggest themselves to thoseskilled in the art, may be made in the form, details of construction andar, rangement of the parts without departing from the spirit of theinvention, or the scope of the broadest of the appended claims.

What is claimed is:

1'. In combination, in a clutch operating device, a pair of laterallymovable plates whose relative lateral movement controls the operation ofthe clutch, a plurality of rolling members interposed between saidplates to produce such relative lateral movement, means integral withsaid plates for holding each of said rolling members isolated from theothers, and means including a rod movable along the axis of the clutchto increase the lateral projections on said plates, said projectionsload thereon and thereby render said rollers effective to produce saidrelative lateral movement.

2. In combination, in a clutch operative device, a pair of laterallymovable plates whose relative lateral movement controls the operation ofthe clutch, a plurality of rolling members interposed between saidplates to produce such relative lateral movement, means integral withsaid plates for holding each of said rolling members isolated from theothers, said integral means comprising cluding a rod movable along theaxis of the clutch to increase the load thereon and thereby cause one ofsaid plates to move toward said iixed plate as the load is applied, andresilient means interposed between said fixed and movable plate foryieldably opposing such movement and thereby causing pressure to beapplied to the clutch.

4. In combination, in a clutch operating device, a pair of laterallymovable plates, a third plate xed against movement laterally, said platecontrolling the operation of the clutch, means including a rod movablealong Vthe axis of the clutch to increase the load thereon and therebycause one of' said plates to move toward said fixed plate as the load isapplied, and resilient means interposed between said ilxed and movableplate for yieldably opposing such movement, said resilient means alsobeing yieldable to compensate for variation in the torque capacity oithe clutch due to thermal expansion therein.

Y FRANCIS LINDER.

